Osteosynthesis implants for the treatment of fractures, correction of malpositions, etc. made of biocompatible metals, such as titanium or titanium alloys or stainless steel, have long been known and used on a large scale. Permanent implants made of such materials remain in the body over the period of time for which they are required for stabilization of the fracture and can lead to complications and may require additional interventions for explantation. Furthermore, they permanently hold the fracture gap free from mechanical stresses and thus prevent a certain mechanical stimulation, which appears to be beneficial to the healing of the fracture.
On account of these and other disadvantages, efforts have long been made to develop optimal absorbable osteosynthesis implants. In particular, polymers have been taken into consideration as material for absorbable implants of this type. Polymers generally have a much lower rigidity than metal materials, whereby polymeric implants must have larger cross sections than metal implants having identical rigidity.
Degradable implants made of magnesium have currently proven to be successful for use as coronary stents. Compared to vascular implants, osteosynthesis implants have a much larger volume. High quantities of degradation products, particularly hydrogen, are thus produced during the degradation, which are problematic and cannot be absorbed quickly enough by the body.
WO 2010/034098 A1 discloses a biodegradable medical implant that can be embodied inter alia as an osteosynthesis implant and is formed from fine-grained metal and fine-grained polymeric material. The metal material can be embedded as small particles, fibers or flakes in a polymeric body.
US 2011/0054629 A1 describes a composite implant that has a porous structure which is filled microscopically with a biodegradable alloy or magnesium. The porous main structure can be produced from a metal, a ceramic or a polymer.